Study of relaxations in epoxy polymer by thermally stimulated depolarization current (TSDC) and dielectric relaxation spectroscopy (DRS)

Thermally stimulated depolarization current (TSDC) and dielectric relaxation spectroscopy (DRS) techniques were employed to study the relaxations and the conductivity phenomena in epoxy-based polymer. In addition to the primary α relaxation process associated with the glass–rubber transition, significant interfacial relaxation and ionic conduction process have been revealed. The ac conductivity is temperature and frequency dependent and shows a dc plateau at low frequencies. Above the glass transition temperature, dc conductivity is described by a Vogel–Tamman–Fulcher–Hesse (VFTH) equation while it shows Arrhenius behaviour at higher temperatures.